Assessment of Economic Losses Associated With Nitrogen Leaching in Agricultural Land in Latvia

Abstract

Water is significantly important resource in everyday life. Parameters that characterize the quality of water resources are affected by human activities. In Latvia, water pollution with nutrients is often related to agricultural activities. As water circulation is sustained and uninterrupted process, nitrogen compounds are lost throughout the hydrographic network and transported both locally and internationally. Increased levels of nitrogen in the water lead to intensive eutrophication processes in the inland water bodies and the Baltic Sea, therefore, availability of clean water is decreasing. It is necessary to minimize and prevent water pollution as much as possible. The aim of this research is to evaluate the economic losses caused by nitrogen leakage through agricultural drainage systems in Latvia. For this purpose, water protection regulations and agricultural runoff monitoring data are examined. Evaluation process of the economic losses includes a comparison of the maximum extent permitted rates of nitrogen application with the theoretical optimum application rates and application rates determined at the research sites. For calculations ammonium nitrate was used as a type of fertilizer. From the results of this research it can be concluded that in about 41% the amount of nitrogen needed to reach the current yield level was exceeded. In addition, on average 13.2% and 15.4% of nitrogen applied annually as mineral fertilizers are lost through the subsurface drainage systems at the Berze and Mellupite research sites, respectively. This causes economic losses to farmers on average 61.13 EUR ha-1 year-1.

Temporal Trends in Nitrogen Concentrations and Losses from Agricultural Monitoring Sites in Latvia

“…Previous study indicates that there is a positive correlation between annual precipitation and discharge for the subsurface drainage fields at the Berze, Mellupite, and Vienziemite study sites with correlation coefficients of 0.75, 0.82, and 0.53, respectively [5]. Therefore, annual mean water discharge varies in different study sites according to meteorological and hydrological differences.…”

“…Artificial removal of water from agricultural lands by agricultural drainage leads to external nutrient inputs causing eutrophication in downstream water bodies. Earlier study shows that there is an increasing ____________________________________________________________________________ 2020 / 24 164 trend in fertilizer application -represented by a moderately close, positive, linear relationship between total fertilizer application and sown area indicating the intensification of production [5].…”